...Xiao-Qiang GUO, Wei-Yang WU, He-Rong GU Yanshan University Phase locked loop and synchronization methods for gridinterfaced converters: a review Abstract. Phase locked loop and synchronization techniques are one of the most important issues for operating grid-interfaced converters in practical applications, which involve Distributed Power Generation Systems, Flexible AC Transmission Systems (FACTS), and High Voltage Direct Current (HVDC) Transmission, and so on. This paper presents a comprehensive review of the recently developed phase locked loop and synchronization methods, then a comparison and selection guide are provided. Finally, a list of more than 40 technical papers is also appended for a quick reference. Streszczenie. Techniki PLL i synchronizacji są ważnymi elementami przetworników w systemach sieciowych, takich jak: rozproszonych systemach mocy, FACTs czy HVDC. Artykuł przedstawia przegląd tego typu metod a następnie porównanie tych metod. Na końcu ponad 40 podstawowych artykułów z tej tematyki jest przedstawionych.(Metody synchronizacji i PLL w przetwornikach sieciowych – przegląd). Keywords: Grid-interfaced converters, phase locked loop, synchronization Słowa kluczowe: uchłady PLL, synchronizacja. Introduction The basic phase locked loop (PLL) concept was originally published by Appleton in 1923 and Bellescize in 1932, which was mainly used for synchronous reception of radio signals [1-2]. After that, PLL techniques were widely used in various industrial...
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...An Integrated Navigation Systems for Underwater Vehicles Based on Inertial Sensors and Pseudo LBL Acoustic Transponders Pan-Mook Lee, Bong-Huan Jun, Hyun Taek Choi and Seok-Won Hong Korea Research Institute of Ships and Ocean Engineering, KORDI, Republic of Korea Abstract - This paper presents an integrated underwater navigation system for underwater vehicles using inertial sensors and range sonar. We supposes that two acoustic transponders, called pseudo long baseline (LBL) system, are installed at two reference stations on sea bottom or below surface and/or ice. The navigation system is based on a strap-down inertial measurement unit (SD-IMU) mounted on an underwater vehicle and assisted with auxiliary navigation sensors, such as Doppler velocity log (DVL), depth, and heading sensors. Range measurement transducers are additional auxiliary navigation sensors. Using the two range measurements, the proposed navigation system will be able to improve the performance of conventional IMU-DVL navigation systems for long-time operation of underwater vehicles, and useful even without DVL information. An extended Kalman filter was adopted to propagate the error covariance, to update the measurement errors, and to correct the state equation when the external measurements are available. Simulations were conducted with the 6-d.o.f. nonlinear numerical model of an AUV in lawn-mowing survey mode under current flow condition. Navigation performance is surveyed for the...
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...most of hiring agency are not interested with because it may seems unprofitable and not aligned with their reputation of well-known hiring agencies. As a result, Sindy faced with minimum competition in the market. In addition, the fact that most of Sindy clients were supermarkets and food courts which consistently searching for people for various low level positions such as shop assistants, cashiers and others also benefited her as she able to have fifteen positions per week to be advertise, and that was three times higher than the number of positions she was estimated in her budget which is five positions per week. Refer to Exhibit 4: Cost Recovery Comparison. Estimations-Low Operating Cost Scenario | Actual | 5% Charge | 10% Charge | 30% Charge | Registration Fee Per Position | 160 | 160 | 160 | 160 |...
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...multi-phase (e.g. 3phase). • Output can be made fixed or variable • Applications: DC welder, DC motor drive, Battery charger,DC power supply, HVDC Power Electronics and Drives (Version 3-2003), Dr. Zainal Salam, 2003 2 Single-phase, half-wave, R-load + vs _ vs + vo _ π vo io 2π ωt Output voltage (DC or average), V Vo = Vavg = 1 Vm sin(ωt )dωt = m = 0.318Vm 2π 0 π Output voltage (rms), Vm 1 (Vm sin(ωt )dωt ) = = 0.5Vm Vo , RMS = 2π 0 2 Power Electronics and Drives (Version 3-2003), Dr. Zainal Salam, 2003 3 π π 2 Half-wave with R-L load i + vR _ + vL _ + vo _ + vs _ Vm sin(ωt ) = i (ωt ) R + L i (ωt ) = i f (ωt ) + in (ωt ) di (ωt ) dωt First order differential eqn. Solution : KVL : vs = v R + v L i f : forced response; in natural response, From diagram, forced response is : i f (ωt ) = where : Z = R 2 + (ωL) 2 Vm ⋅ sin(ωt − θ ) Z θ = tan −1 ωL R Power Electronics and Drives (Version 3-2003), Dr. Zainal Salam, 2003 4 R-L load Natural response is when source = 0, di (ωt ) i (ωt ) R + L =0 dωt which results in : in (ωt ) = Ae −ωt ωτ ; τ = L R Hence Vm i (ωt ) = i f (ωt ) + in (ωt ) = ⋅ sin(ωt − θ ) + Ae −ωt ωτ Z A can be solved by realising inductor...
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...UNIVERSITY OF MIAMI TONALITY ESTIMATION USING WAVELET PACKET ANALYSIS By Vaibhav Chhabra A Research Project Submitted to the Faculty of the University of Miami in partial fulfillment of the requirements for the degree of Master of Science Coral Gables, Florida May 2005 UNIVERSITY OF MIAMI A research project submitted in partial fulfillment of the requirements for the degree of Master of Science TONALITY ESTIMATION USING WAVELET PACKET ANALYSIS Vaibhav Chhabra Approved: ________________ Ken Pohlmann Professor of Music Engineering _________________ Dr. Edward Asmus Associate Dean of Graduate Studies ________________ Colby Leider Assistant Professor of Music Engineering _________________ Dr. Paul Mermelstein Professor of Electrical Engineering DEDICATION They say that one’s experience is what defines an individual. After all, you are what you are because of your experiences. On that note I would like to dedicate this work to all those who have contributed to my experience in this journey. For what I have learned has laid the foundation for what I will learn. I would also like to thank my family who has always been supportive of me, my brother Ruchir who is a natural send-master, Papa and Ma thanks for keeping the faith. All the Chacha’s, Chachi’s and cousins, thank you all for the support. Next on my thank you list are my Tae Kwon Do buddies. Sensei Jeff thanks for all of your advice, some day I’ll be teacher like you. Rico, training...
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...04/12/02 57:020 Mechanics of Fluids and Transfer Processes Laboratory Experiment #3 Measurement of Pressure Distribution and Lift for an Airfoil Purpose The objectives of the experiment are to examine the surface pressure distribution and to compute the lift force acting on the airfoil. Test Design A body immersed in a flowing fluid is exposed to both pressure and viscous forces. The sum of the forces that acts normal to the free-stream direction is the lift, and the sum that acts parallel to the free-stream direction is the drag. The geometric and dynamic characteristics of airfoils are shown in Figure 1. This experiment is concerned with computation of the lift on a stationary airfoil mounted in the test section of a wind tunnel. We will consider only two-dimensional airfoils where tip and root effects are neglected. Because the velocity of the flow over the top of the airfoil is greater than the free-stream velocity, the pressure over the top is negative. This follows directly from the application of Bernoulli’s equation. Similarly the velocity along the underside of the airfoil is less than the free-stream velocity and the pressure there is positive. Hence, both the negative pressure over the top and the positive pressure along the bottom contribute to the lift. There are a variety of ways to measure lift. In this experiment, the lift force, L, on the airfoil will be determined by integration of the measured pressure distribution over the airfoil’s...
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...Electrical Engineering Department 2008 Annual Research Review 28 January 2008 Spectrum Sensing Design for Cognitive Radios Prof. Danijela Cabric danijela@ee.ucla.edu Spectrum Utilization Power Spectrum Density (dBm/Hz) -100 -110 -120 -130 -140 -150 0 1 2 3 4 5 6 GHz Freq (GHz) Utilization(%) 0~1 54.4 1~2 35.1 2~3 7.6 3~4 0.25 4~5 0.128 5~6 4.6 Even though the spectra is allocated it is almost unused Cognitive Radios can make better use of the spectrum How Does a Cognitive Radio Operate? PU1 PU3 CR1 PSD PU2 CR2 Primary Cognitive PU4 Frequency Sense the spectral environment over a wide bandwidth Transmit in “white space” & Adapt bandwidth and power Detect if primary user appears Move to new white space Cognitive Radio System Design Network Management Sensing MAC Sensing Signal Processing Sensing radio Spectrum Allocation Network Link Layer Wideband signaling Wideband radio Physical Layer Spectrum sensing is the key enabling functionality How do we implement spectrum sensing in a system? Spectrum Sensing Problem Primary User Cognitive Radio users must guarantee non-interference requirement Tx Rx CR CR Decoding SNR Sensing SNR distance Distance and channel not known Cognitive radio can only observe (sense) primary system Tx signals Need to sense signals in highly negative SNR Sensing SNR < Decoding SNR – worst case channel Sensing SNR < [5dB to 20 dB] – [20 dB to 40 dB] = [-35...
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... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii iii iv 1 1 1 1 2 3 4 4 5 5 5 6 6 7 7 8 9 9 9 12 13 13 15 16 17 17 17 18 19 2 Models of stationary processes 2.1 Purely indeterministic processes . . . . . . 2.2 ARMA processes . . . . . . . . . . . . . . 2.3 ARIMA processes . . . . . . . . . . . . . . 2.4 Estimation of the autocovariance function 2.5 Identifying a MA(q) process . . . . . . . . 2.6 Identifying an AR(p) process . . . . . . . . 2.7 Distributions of the ACF and PACF . . . 3 Spectral methods 3.1 The discrete Fourier transform . . . . . . . . . . . . . . . . . . . . . . 3.2 The spectral density . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Analysing the effects of smoothing . . . . . . . . . . . . . . . . . . . . 4 Estimation of the spectrum 4.1 The periodogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Distribution of spectral estimates . . . . . . ....
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...Whisenant T. Maples English 101 15 October 2010 Arguments. What do they achieve? Nothing really. You have two sides of every coin, but who is to say which side is the correct side? It’s all a matter of opinion. You can ask either side of any issue and they both will quote facts and figures that will prove they are right. You want proof? Let’s take a look at the history of humanity. You have two individuals who have opposing ideas. This leads to what we call an argument. Not that big of a deal, but then it gets heated enough and you have a fight. Still not that big of a deal, right? Until you get enough people on both sides and then you have what’s called a war. Take a look at WWII. You had Hitler and his generals. They decided that a group of people no longer needed to exist, so they set out on a campaign to exterminate a race of people. Six million Jews died because one man thought they were inferior. But they weren’t the only ones. Along with the Jews, three million Polish, three million Russian POW’s, and an estimated eight million other European’s were also slaughtered by Hitler’s Regime. (1) This doesn’t take into account the soldiers that died either to stop Hitler or to expand his campaign. What did it accomplish? Look at the lives that were lost due to one man’s ideals and the efforts the world went to stop him. Then there is the Korean War. It started in June of 1950 when North Korea invaded South Korea because one side thought that Communism...
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...Who is the biggest loser? Today, about 240 families lost a loved one to a tobacco-related illness. That’s an estimated 87,600 deaths in a year. In 2011, the country earned around Php26 billion worth of taxes from the tobacco industry, while revenue from cigarette manufacturers amounted to approximately Php31 billion. How much does life cost? For each life lost to tobacco use, the tobacco industry earned Php353,881.28. Is it worth it? This does not even account for the annual health costs and productivity losses from tobacco-related deaths and diseases that range from Php148 billion to Php314 billion. No monetary equivalent can also be juxtaposed to the hours of painful treatment just to manage the diseases, nor the time and energy a family member spends to care for the loved one. More so, these numbers do not even reflect the pain of losing someone you love. But for decision-makers, these exact figures and immeasurable realities are not compelling enough to pass the necessary measures to reduce tobacco use. Instead, the most marginalized and the poorest sectors are pitted against each other to rationalize inaction - tobacco victims versus farmers, workers against children and youth. Life versus livelihood. The battle of the sectors has been the easiest tactic to muddle the discourse on amendments to excise taxation. What we fail to remember is that all of these sectors - farmers, urban poor, youth, children, and workers are the tobacco victims. They are the...
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...1. Introduction The aims of this experiment are to use diffraction gratings to measure the wavelength of light. Visible light is an electromagnetic radiation which is visible to human eye. Light source of different colors and wavelengths are often produced by a visible light source. A light source such as incandescent light bulb utilizing hot metal filaments is consisted of a continuous distribution of lights with a range of wavelengths, hence forming a white light. On the other hand, light produced from a mercury lamp and helium lamp contains only several discrete wavelength components. A number of methods can be adopted to measure the separated wavelength components. However, for this experiment, we will be focusing on using diffraction grating in which light from the above three types of sources will be dispersed into its constituent colors through diffraction grating and then we are able determine the wavelength of light. 2. Objective 2.1. By comparing and analyzing the pattern of the three different light sources, we can understand the difference between a continuous and a discrete spectrum. 2.2. To be able to understand that the light produced has a spectrum that is a characteristic of the elements from the experiment results of mercury lamp and helium lamp. 2.3. To obtain or calculate the average spacing, given the characteristics wavelengths of a mercury lamp from our first experiment. 2.4. To determine the characteristic wavelengths of a helium lamp...
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...Dear Charles, Here's a possible rewrite of your thesis: "This paper will examine Augustine's teachings about 'conferred faith' upon infant during baptism. My claim is that Paul misrepresented Paul's teachings on the family's effect upon the holiness of the child." You'll find the "claim" in chapters 1-14 of Turabian's Manual, which is something that our rubric doesn't bring up, but I think it's a good technique. I notice that you have Greek written in Times New Roman font. I have seen other students do this. I have never been able to figure out how this is done. I notice that when I try to add a letter than it comes out in Latin script. These are quotations that you've pasted. This is amazing. I don't know how they do this! Let me know if you can help me! The only defect in this paper that I want to point out is that much of your paper is not really about Augustine's teaching on infant baptism. All subsequent developments of his teachings really have nothing to do with what happened in Augustine's head. Let's take Pannenberg as an example. He may have followers up there in Lutheran country where you minister. His ideas are influenced by Augustine, but Augustine was not a Lutheran. Some seem to think he was a Lutheran or a Calvinist, but they deceive themselves. You must, of course, take Paul into account because Augustine worked with Paul's writings. Paul was a source that Augustine used—or better, abused or misused, as you and argue. Students find it impossible to focus on one...
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...solely dedicated towards marijuana-related prosecutions. The third major cost for the criminalization of marijuana are sections that pertain to the corrections budget, which is dedicated towards the incarceration of prisoners who have been charged with marijuana-related offenses. A practical indication of this part would be the fraction of prisoners that have been incarcerated for marijuana-related offenses. Although if marijuana were to be legalized, governments would have the power to levy taxes, specifically sin taxes, on the sale and production of marijuana and enforcement costs would be insignificant. Therefore, tax revenue would increase as government expenditure would decrease. According to prohibitioncosts.org, the savings within government expenditure and the boost in tax revenue would develop through replacing criminalization of marijuana with an establishment in which marijuana would be legalized, but regulated and taxed like other goods. The report listed estimations, establishing that the legalization of marijuana would end up decreasing government expenditure by $7.7 billion yearly. In addition to the decrease in government expenditure, legalization of marijuana would furthermore generate a tax revenue of $2.4 billion yearly if marijuana were imminently taxed like all other goods along with $6.2 billion yearly if marijuana were taxed on amounts that are proportionate to those on tobacco, alcohol, and gambling. These budgetary influences depend on an assortment of expectations...
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...2011 ECTC Proceedings ASME Early Career Technical Conference Hosted by ASME District E and University of Arkansas Support Provided by the ASME Old Guard and the Committee on Early Career Development March 31-April 02, 2011, Fayetteville, AR DESIGN OF AN AUTOMATIC LANDING SYSTEM FOR A UAV USING FEEDBACK LINEARIZATION METHOD Ghassan. Atmeh1 and Zeaid, Hasan2 1 Mechanical and Aerospace Engineering Department, The University of Texas at Arlington, Arlington, Texas, email: atmehg@gmail.com 2 Mechanical Engineering Department, Texas A&M University, College Station, Texas, email: zeadnws@hotmail.com CmδE Cn CY CYo CYβ CYδR CYδA c d D g J L L m q R = = = = = = = = = = = = = = = = = Pitching moment coefficient due to elevator deflection Yawing moment coefficient Side-force coefficient Side-force coefficient for zero angle of attack Side-force coefficient contribution due to side-slip angle Side-force coefficient contribution due to rudder deflection Side-force coefficient contribution due to aileron deflection Wing cord (m) UAV displacement from glide path (m) Drag fore (N) Acceleration due to gravity (m/s2) Inertia matrix Lift force (N) Applied moment vector (N.m) Mass (kg) Dynamic pressure Slant range (m) ABSTRACT An automatic landing system for an unmanned aerial vehicle (UAV) is presented in the following paper. The nonlinear aircraft model with elevator deflection and thrust as control inputs is established using the appropriate aerodynamic data, followed by the definition...
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...CHARACTERISTICS PERFORMING THE PLATE BEARING TEST Summary: In the international literature there is often confusion between the terms Modulus of Elasticity EYoung and Modulus of Deformation EDef for homogenous, isotropic masses, which, sometimes, plainly referred as Modulus E, without any further explanation. In this paper a distinction between the EYoung and the EDef is being done and the interest is concentrated in the Plate Bearing Test, which is commonly used in highway earthworks. Moreover, a soil classification diagram is given, in which the soils are classified by their shear strength parameters and their behavior, as totally elastic or elastoplastic, under specific loading applied by rigid circular plate. Finally, a method for the estimation of the soil parameters is proposed, using only the in-situ Plate Bearing Test. The study and the documentation were supported by a presentation of theoretical examples, based on the Finite Element Method. 1. INTRODUCTION In highway earthworks the knowledge of the Modulus of Elasticity of the soils is very important, whether the projects are in the stage of design, construction or compaction check and this is required to be obtained by an easy manner. Due to the complexity and difficulty in determining the Modulus of Elasticity in the laboratory by the Triaxial Test, which is usually not available on the worksite, the common practice for the designer is to determine the Modulus of Deformation with the in situ and easier Plate Bearing...
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